Chain lock with signal for door

ABSTRACT

A metal base plate has a keyhole anchor for a door chain and is carried by a mounting plate. A signal lever on the base plate has a flexible ear positioned to be engaged by the anchor knob on the end of the chain. An on-off lever on the base plate selectively locks the signal lever against movement, so that unauthorized movement of the chain and its anchor end either moves the signal lever to complete an alarm circuit, or bends the flexible ear on the signal lever without releasing the chain anchor. The mounting plate carries retainers and contacts for batteries that are connected in circuit with an audio signal on the base plate and a fixed switch contact on the base which coacts with the signal lever.

United States Patent I Vand erveer CHAIN LOCK WITH SIGNAL FOR DOORInventor:

Appl. No.: 122,654

Int. Cl. .......G08b 13/08 Field of Search ...340/274, 282, 276;ZOO/61.93,

ZOO/61.68; 116/14 [5 6] References Cited UNITED STATES PATENTS 3,585,6256/1971 Prinsky et a] ..340/274 3,569,950 3/197l Betz ..340/274 3,406,38610/1968 Hawkins ..340/276 Assignee: Leigh Products, Inc., Coopersville,

US. Cl. ..340/274, ZOO/61.93, 340/276 [151 3,705,421 [451 Dec.5 1972Primary Examiner-John W. Caldwell Assistant Examiner-Glen R. Swann, ll]Attorney-Austin A. Webb [5 7] ABSTRACT A metal base plate has a keyholeanchor for a door chain and is carried by a mounting plate. A signallever on the base plate has a flexible ear positioned to be engaged bythe anchor knob on the end of the chain. An on-off lever on the baseplate selectively locks the signal lever against movement, so thatunauthorized movement of the chain and its anchor end either moves thesignal lever to complete an alarm circuit, or bends the flexible ear onthe signal lever without releasing the chain anchor. The mounting platecarries retainers and contacts for batteries that are connected incircuit with an audio signal on the base plate and a fixed switchcontact on the base which coacts with the signal lever.

7 Claims, 5 Drawing Figures PATENTEDMB 5 m2 sum 1 0F 2 FREDRIC INVENTOR.

E .V ANDERVEER BY I M ATTORNEY PAIENTEDnEc 5 m2 mm 2 or z INVENTOKFREDRIC B. VANDERVEER a ATTORNEY CHAIN LOCK WITH SIGNAL FOR DOOR PRIORART Safety chain locks to limit the opening motion of doors have beenprovided with battery operated signals and switching devices to sound analarm when a door secured by the chain starts to open. These deviceshave operated on the principal that movement of the door relative to theend of the chain causes the end of the chain to touch a terminal andcomplete the alarm circuit through the end of the chain or through themovable anchor which secures the chain to the door.

OUTLINE or INVENTION The present invention provides an arrangement inwhich movement of the anchor button on the end of the chain relative toits retaining anchor on the door functions to mechanically shift aswitch member of a signal unit on the door, completing an alarm circuit.Thus the coacting anchor part on the door and the chain functiondirectly to secure the door for limited opening movement. The electricalswitch and circuit parts associated with the signal carry no mechanicalloads for securing the door, and can be of lighter construction.

Further, the invention provides a yieldable drive connection between theanchor on the end of the chain and the switch lever, which enablestheswitch lever to be separately and selectively locked in open positionwithout interfering with the door securing function of the chain and theanchor on the door. Thus, the chain lock assembly can be selectivelyadjusted to sound the alarm, or not, when the door is opened to thelimit permitted by the chain.

Additional desirable features of the lock and signal permit the use ofeconomical parts and retaining structure for the battery, alarm, andtheir circuit connections, and easy assembly into the complete lock andsignal as will be described. 1

DESCRIPTION The drawings, of which there are two sheets, illustrate apreferred form of the invention.

FIG. 1 is a fragmentary elevational view of the lock and signal, inoperative position on a door and door frame.

FIG. 2 is an elevational view of the door anchor and signal as mountedon the door with the cover removed.

FIG. 3 is a fragmentary vertical cross sectional view taken along theplaneof the line 3-3 in FIG. 1.

FIG. 4 is an enlarged front elevational view of the door anchor, switchlever, on-off lever and the related retaining parts for the battery,circuit connections and mounting structure, with the selective signalcontrol in on position.

FIG. 5 is a fragmentary front elevational view of the switch lever andthe selective on-off lever in of position.

The major parts of the lock consist of a casing 1, attached to the frame2 of a door, a fixed anchor 3 attached to the casing 4 of the doorway,and a chain 5 permanently secured to the fixed anchor and having areleasable anchor 6 in the form of a headed stud on its free end. Thereleasable chain anchor 6 is selectively engageable in a keyhole slot 7in a door anchor 8 or in a storage hole 9 in the fixed anchor The casing1 consists of a rear mounting plate 10, which is conveniently made ofmolded plastic. Ribs 11 along the sides of the mounting plate havedetents 12 which springably engage the edges of the molded cover 13. Theupper wall of the cover is cut away as at 14 exposing the door anchor 8and the keyhole slot 7. Wlthin the casing and behind the cover 13, themounting plate has integral forwardly projecting vertical side ribs 15with opposed dovetailed slots 16. therein. See FIG. 4.

The slots slidably receive and retain folded metal contact elements 17,18 and 19 in position to engage the ends of batteries 20 and 21.Vertically spaced converging flexible ears 22 formed integrally on themounting plate retain the upper and lower sides of the two batteries inthe casing.

The anchor 8 is formed as a forwardly and downwardly inclined flange onthe upper crosspiece of a generally T-shaped base plate 23. The plate 23is of sturdy metal construction to withstand the pull of the chain 5 andthe movable anchor 6 thereon, and is secured to the frame of the door byscrews 24 that pass through the mounting plate 10. Other screws or bolts25 secure the base plate to the mounting plate prior to installation ofthe lock on the door. Note that the mounting can be reversed to mountthe casing 1 on the doorway casing and the anchor 3 on the frame of thedoor.

The vertical stem 26 of the T-shaped base plate is lapped flush with themounting plate, between the ribs 15 and behind the batteries to aforwardly offset pad end 27 (See FIG. 3) which constitutes a mountingconnection for an audio signal device 28 such as a buzzer. Theconnection of the signal to the pad constitutes an electrical connectionfrom one side of the signal to the base plate. A wire 29 connectedelectrically to the other side of the signal extends to the terminalclip 17 to form a series connection between the signal and the batteriesand the base plate. The other end of the series is the terminal 19 whichhas a contact flange 30 located forwardly of one side of the cross barof the T-shaped base plate.

Secured to the base plate 23 in lapped relation to its upper end is aswitch lever 31, held rockably in pace by a rivet 32. One arm 33 (SeeFIG. 4) of the lever has a forwardly turned contact flange 34 in opposedcoacting relation to contact flange '30. An opposite arm 35 of theswitch lever projects to underneath an on-off lever 36 to be described.The center of the switch lever extends upwardly in an arm 37 with aforwardly and downwardly inclined flange 38 on its upper end. Extendinglaterally from the flange 38 is an upwardly inclined finger 39 with atab 40 on its upper end in closely spaced relation below the flange 8and slot 7. The finger and tab are thus in the path of movement of themovable anchor 6 along the slot, and tension on the chain 5 can forcethe switch lever and its contact flange 34 into engagement with theterminal 30, to complete the circuit to the alarm signal 28.

The on-off lever 36 permits the safety chain lock to be used withoutsounding the alarm signal. It also turns off the alarm. The lever issecured in lapped relation to the cross piece of the base plate by arivet 41. An actuating finger piece 42 projects through a notch in thecover'l3 to be exposed on the outside of the casing; while a forwardlyturned stop flange 43 overlies the arm 35 of the switch lever inblocking relation thereto when the lever 36 is in off" position.Whenever the lever 36 and its flange 43 are in blocking relation to theswitch lever, the movable anchor 6 on the chain can still slide alongthe slot 7 by deflecting the arm 39 downwardly as shown by the dottedline position in FIG. 5. Similarly, the switch lever 31 and its contactflange 34 can be moved to off position while the safety chain isextended and the anchor 6 is in engagement with the finger 39. Thisaction is made possible by flexing of the relatively narrow finger 39and its corresponding narrow connection to the flange 38 f the switchlever. It is thus possible for the householder to turn off the alarmwhile leaving the safety chain in place while he identifies the personwho opened the door and sounded the alarm in the first place.

What is claimed as new is:

l. A safety chain lock and alarm for doors and including a chain with amovable anchor comprising a casing having a battery and an electricalsignal connected in series therein,

a metal base plate secured in said casing and having a flange at one endbent forwardly and defining a keyhole slot exposed through one wall ofsaid casing and adapted to removably receive said movable anchor,

one side of said signal being electrically connected to said base plate,

a switch lever pivotally and electrically connected to said base andhaving a contact swingable with the lever into electrical contact withthe opposite side of said battery from said signal,

and an actuating arm on said switch lever eccentric to the pivot of thelever and extending to adjacent said flange on said base plate and inthe path of said movable anchor when said anchor moves along saidkeyhole slot.

2. A chain lock and alarm as defined in claim 1 in which said switchlever has another arm formed thereon,

and a signal interrupting lever pivoted on said base plate and having astop arm movable into blocking relation to said switch lever to hold thecontact of the latter open,

said interrupting lever having an operating arm projecting through theside of said casing,

said actuating arm being springable relative to the remainder of saidswitch lever to permit passage of of said battery one of said clipshaving a portion forming the contact engageable with the contact portionof said switch lever,

and another of said clips having alarm electrical connection connectedto the opposite side of said signal from said base plate.

4. A chain lock and alarm as defined in claim 3 in which said base plateis a T-shaped member with its stem secured in lapped relation to thefront side of said flat back and between said retaining flanges,

the stem of said T-shaped member extending beyond said retaining flangesand having said signal electrically and mechanically connected to itslower end.

5. A chain lock and alarm as defined in claim 4 in which said casing hasa removable cover having a snap engagement with the edges of said flatback.

6. A chain lock and alarm as defined in claim 1 in which said switchlever is a flat metal member with a rivet forming the pivotal connectionbetween the midportion of the lever and the upper part of said baseplate,

a forwardly turned flange on one end of said flat metal member formingthe swingable contact on the switch lever,

and an upwardly extending coplaner arm near the center of said flatmetal member,

said actuating arm being folded forwardly from the top of said coplanerarm with an upwardly and laterally inclined finger on one side of aforwardly folded portion extending to adjacent the slot in the flange onsaid base plate.

7. A chain lock and alarm as defined in claim 2 in which said switchlever is a flat metal member with a rivet forming the pivotal connectionbetween the midportion of the lever and the upper part of said baseplate,

a forwardly turned flange on one end of said flat metal member formingthe swingable contact on the switch lever,

and an upwardly extending coplaner arm near the center of said flatmetal member,

said actuating arm being folded forwardly from the top of said coplanerarm with an upwardly and laterally inclined finger on one side of aforwardly folded portion extending to adjacent the slot in the flange onsaid base plate.

UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION i Patent No.",705,421 Dated December 1972 l t Fredric B. Vanderveer It is certifiedthat errorappears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

On the cover sheet [72] "Fredic" should read Fredric ,v

Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

EDWARD M. FLETCHER, JR ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents F ORM PO-1050 (10-69) USCOMM-DC 60376-P69 w us GOVERNMENTPRINTING OFFICE: 1959 mass-334, l

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION P n N I 1 3,705,421 I Dated December 5, 1972 InventQr( Fr ed-Tic CB. VandeIVeer Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover sheet [72] "Fredic" should read Fredric Signed and sealedthis 8th day of May 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JRV. I I ROBERT GOTTSCHALK Attesting OfficerCommissioner of Patents FORM PO-1050 (10-69) U$COMM-DC 60376-P69 w us.GOVERNMENT PRINTING OFFICE I969 0-366-334,

1. A safety chain lock and alarm for doors and including a chain with amovable anchor comprising a casing having a battery and an electricalsignal connected in series therein, a metal base plate secured in saidcasing and having a flange at one end bent forwardly and defining akeyhole slot exposed through one wall of said casing and adapted toremovably receive said movable anchor, one side of said signal beingelectrically connected to said base plate, a switch lever pivotally andelectrically connected to said base and having a contact swingable withthe lever into electrical contact with the opposite side of said batteryfrom said signal, and an actuating arm on said switch lever eccentric tothe pivot of the lever and extending to adjacent said flange on saidbase plate and in the path of said movable anchor when said anchor movesalong said keyhole slot.
 2. A chain lock and alarm as defined in claim 1in which said switch lever has another arm formed thereon, and a signalinterrupting lever pivoted on said base plate and having a stop armmovable into blocking relation to said switch lever to hold the contactof the latter open, said interrupting lever having an operating armprojecting through the side of said casing, said actuating arm beingspringable relative to the remainder of said switch lever to permitpassage of said movable anchor along said keyhole slot when movement ofthe switch lever is obstructed by said interrupting lever.
 3. A chainlock and alarm as defined in claim 1 in which said casing has a flatback of insulating material to which said base plate is mechanicallyconnected, aligned holes in said base plate and said flat back adaptedto receive screws for fastening said casing to a part of a door,retaining flanges on said back arranged to receive and retain saidbattery, terminal supporting flanges on said back plate having dovetailslots formed therein in opposed laterally spaced and forwardly openingrelation, and metal terminal clips retainingly received in said slots toelectrically contact the electrical terminals of said battery, one ofsaid clips having a portion forming the contact engageable with thecontact portion of said switch lever, and another of said clips havingalarm electrical connection connected to the opposite side of saidsignal from said base plate.
 4. A chain lock and alarm as defined inclaim 3 in which said base plate is a T-shaped member with its stemsecured in lapped relation to the front side of said flat back andbetween said retaining flanges, the stem of said T-shaped memberextending beyond said retaining flanges and having said signalelectrically and mechanically connected to its lower end.
 5. A chainlock and alarm as defined in claim 4 in which said casing has aremovable cover having a snap engagement with the edges of said flatback.
 6. A chain lock and alarm as defined in claim 1 in which saidswitch lever is a flat metal member with a rivet forming the pivotalconnection between the mid-portion of the lever and the upper part ofsaid base plate, a forwardly turned flange on one end of said flat metalmember forming the swingable contact on the switch lever, and anupwardly extending coplaner arm near the center of said flat metalmember, said actuating arm being folded forwardly from the top of saidcoplaner arm with an upwardly and laterally inclined fInger on one sideof a forwardly folded portion extending to adjacent the slot in theflange on said base plate.
 7. A chain lock and alarm as defined in claim2 in which said switch lever is a flat metal member with a rivet formingthe pivotal connection between the mid-portion of the lever and theupper part of said base plate, a forwardly turned flange on one end ofsaid flat metal member forming the swingable contact on the switchlever, and an upwardly extending coplaner arm near the center of saidflat metal member, said actuating arm being folded forwardly from thetop of said coplaner arm with an upwardly and laterally inclined fingeron one side of a forwardly folded portion extending to adjacent the slotin the flange on said base plate.